System validation and density fluctuation calibration of Phase Contrast Imaging (PCI) on HL-2A tokamakare presented. Signals from different channels show not only a pronounced modulation of incident laser beam induced by sound wave but also an excellent magnification and low image distortion of optics. Frequency-wavenumber spectrum is achieved by using two-dimensional Fourier transform of time series signals. Conversion relationship between detected signal amplitude and chord integral plasma density fluctuation is 2.35×1013m-2/mV, which promises a suitable signal level at the order of Volts of the PCI in typical HL-2A discharges.
Yu Yi, Gong Shaobo, Xu Min, Yuan Boda, Wu Yifan, Nie Lin, Ke Rui, Ye Minyou, Duan Xuru. System validation of CO2 laser based Phase Contrast Imaging on HL-2A tokamak[J]. Chinese Optics Letters, 2018, 16(12): .
